Lifting-jack



(No Model.)

' P. GRIFFIN.

LIETING JACK. 110.463,385. Patented Nov. 17, 1891.

WWESSES l [mw/ww? am @Ji/757., 'wwm @www 2m ws Nomus paens co.,Mora-mnu., wAsnmMml, n.

UNTTED STATES PATENT OFFICE.

PETER GRIFFIN, OF DAYTON, OHIO.

LlFTlNG-JACK.

SPECIFICATION forming part of Letters Patent No. 463,385, dated November17, 1891.

Application tiled June 15, 1891. Serial No. 396,290. (No model.)

To all whom, t may concern:

Be it known that I, PETER GRIFFIN, a citizen ofthe United States,residing at Dayton, in the county of Montgomery and State of Ohio, haveinvented certain new and useful Improvements in Lifting-Jacks, of whichthe following is a specification, reference being had therein to theaccompanying drawings.

This invention relates to certain new and useful improvements inlifting-jacks.

My improvements have reference to an operating-pawl and aneccentric-lever having means for adjusting its throw; have reference tocombining with a vertically-moving follower a lifting-screw mounted inthe follower; have reference to making the follower of such shape incross-section that it will present a projecting corner or angle adaptedto enter places which the broad flat side would not enter, wherebyobjects may be reached which otherwise would be inaccessible to thefollower, and have reference to certain features of construction in thebase and guides.

In the accompanying drawings, forming a part of this specification, andon which like reference-letters indicate corresponding parts, Figure lrepresents a partial side elevation and a partial sectional viewofmyimproved liftingjack; Fig. 2, a plan view; Fig. 3, aperspective Viewof the follower in detail; andFig. 4, a plan view of the base, guides,and follower with the lifting-screw, detent, and operatinglever removed.

The letter A designates the base -plate, upon which is cast or otherwisesecured guides B, whose arrangement and position are preferably thatshown in Figs. 2 and 4, so that the follower C will have a corner Dstanding opposite the operating-lever, whereby7 a projection or edge isprovided capable of reaching into places which would be inaccessible tothe liat side of the follower. By this posi'- tion and arrangement thedevice is rendered useful in places and at times when otherwise it wouldnot be available to lift objects access -to which is circumscribed.

The guides constitute braces at their lower-` ends in connection withweb H and l.

The lower end of the follower is provided l with a stout arm J, adaptedto extend under objects to be lifted, as when such objects are too lowto get the follower under them. By this means such objects may be lifteduntil their altitude will admit of placing the follower under them, whenthey may be further lifted aswell by the vertical adjustment of thefollower as by the projection upward of the screw K by rotating itthrough one or more levers L, shown in dotted lines, and adaptedto enterholes L in the head M. This screw K is fitted to a screw-threadedopening of suitable length in the follower. Vhen an object difficult ofaccess is to be lifted by the corner of the follower, the screw may berun up until its head is out of the way, or may be removed altogether.

The web F is provided with ratchet-teeth O, with which engage adouble-pointed detent P and a double-pointed pawl Q. The detent ispivoted upon a pin R, carried by the wings E, and is provided with athumb-piece S, and is pressed against the ratchet-teeth by a spring T.The pawl is held in engagement with the teeth by a similar spring U andhas a hand-piece V, and is mounted upon the eccentric VV of aneccentric-lever S. The eccentric has a plurality of holes Y Y of dit'-ferent eccentricity and adapted to be mounted upon a pin Z, carried bywings E. The

eccentric-lever elevates and lowers the pawl t Q with a leverage andwith a length of stroke varying with the particular hole Y or Y in whichthe pin is placed. If a quick movement is desired, the lever is adjustedto receive the pin Z in the more remote hole in the eccentric. If aslower movement is required, the pin will be placed in a hole nearer tothe center. Thus the follower may be actuated with a quick movement andat reduced leverage, or with a slower movement and at an increasedleverage without change of instru- .mentalities the same devices beingused in each case with a mere change of the pin from one hole toanother.

It' .the object to be lifted becomes for some reason too much for theavailable power that can 'be applied to the eccentric-lever, or if thatobject needs to be lifted' to a point intermediate of the positionreached by the follower when moved the height of the thick- TOC ness ofone ratchet-tooth, or if that object must be lifted higher than therange of 1novenient of the follower will aceomplish,tl1en resort may behad to the screw K,-wl1iel1, it will be seen, can be operated with lessresistance t0 the efforts applied to it than incident to the Verticalmovement of the follower.

The operation and advantages of my invention will be understood from theabove.

Having thus fully described my invention, whatI claim as new, and desireto secure by Letters Patent, is-

1. The combination, with a base and guides and wings, of a followermounted in said guides and a lifting-screw mounted in the follower, a.pawl and detent engaging the fol- PETER GRIFFIN. lVitnesses:

EDWARD CURRAN, Il. A. HUNTER.

